1. Field of the Invention
The present invention relates to printing apparatuses and determination methods thereof.
2. Description of the Related Art
Hitherto, printing apparatuses have been known that are provided with a printhead in which a plurality of substrates (printing element substrates) are provided having components such as temperature sensors and heaters (printing elements). In these printing apparatuses provided with printheads, technologies for carrying out temperature control by selectively operating a heater provided in each of the plurality of substrates respectively are known (Japanese Patent Laid-Open No. 10-16230) in which a temperature sensor provided in each of the plurality of substrates respectively is used to selectively detect the temperature of the substrate.
Furthermore, technologies are known (Japanese Patent Laid-Open No. 3-176155) for determining whether or not both the temperature sensor and the heater are operating normally based on temperature changes before and after driving the heater, and print processing is then restricted if there is an abnormality in at least one of these.
Hitherto, methods have been known for selectively obtaining detection signals from the temperature sensor provided in each of the plurality of substrates. However, in determining abnormalities in a substrate (such as in a temperature sensor, heater, drive circuit, or selection circuit for example), in a case for example where there is an abnormality in the selection circuit or the like that selects the detection signal of the temperature sensor provided in each of the plurality of substrates, sometimes an incorrect determination will be made undesirably that apparently operation is normal.